–noun, plural -nies.
A spontaneous diagnosis made by House M.D., triggered by what appears to be random thoughts or actions.

In season 5, episode 18 "Here Kitty", After ruling out multiple illnesses and managing to keep Cuddy from ejecting the patient on suspicion that she's a Münchausen's, House has a housepiphany when he observes Debbie sitting on his warm computer, and determines that the cat was attracted to warmth, explaining the "death visits", as all the victims were exuding heat in some manner (the heat came from the warming blankets placed on the patients).